I am STILL confused: how far east did the ship in “The Claiming” go before the Danes overtook and captured it? The maps make it appear that there is hardly any distance between the southern parts of Denmark that lets into the Baltic. Is this the way that Sidroc’s trading ships went?

The Idrisid ship that kidnapped Ceridwen and Sidroc had made it around the horn of the Danish islands and into the Baltic proper when it was chased down by the Danish drekar. And yes, the reverse of this route is the very same that Sidroc’s trading ships would need to travel to make it to Frankland with those valuable furs and amber and goshawks!